1、Designation: D1245 11D1245 17Standard Practice forExamination of Water-Formed Deposits by ChemicalMicroscopy1This standard is issued under the fixed designation D1245; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of las
2、t revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice describes a procedure for the examination of water-formed deposits by means of chemical microscopy. Thispra
3、ctice may be used to complement other methods of examination of water-formed deposits as recommended in Practices D2331or it may be used alone when no other instrumentation is available or when the sample size is very small.1.2 The values stated in SI units are to be regarded as standard. No other u
4、nits of measurement are included in this standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of re
5、gulatorylimitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Orga
6、nization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D887 Practices for Sampling Water-Formed DepositsD1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD2331 Practices for Preparation and Preliminary Testing of Water-Formed DepositsD23
7、32 Practice for Analysis of Water-Formed Deposits by Wavelength-Dispersive X-Ray FluorescenceD3483 Test Methods for Accumulated Deposition in a Steam Generator Tube3. Terminology3.1 DefinitionsDefinitions: For definitions of terms in this practice relating specifically to water and water-formed depo
8、sits,refer to Terminology D1129.3.1.1 For definitions of terms used in this standard relating specifically to water and water-formed deposits, refer toTerminologyD1129.3.2 Definitions of Terms Specific to This Standard:3.2.1 Certain terms in this practice that relate specifically to chemical microsc
9、opy are described as follows:3.2.2 anisotropic, adjhaving different optical properties in different optical planes.3.2.2.1 DiscussionThese planes are referred to as the alpha, beta, and omega axes.3.2.3 Becke line, na faint, halo-like line that surrounds a crystal when the crystal is mounted in an o
10、il of different refractiveindex.1 This practice is under the jurisdiction ofASTM Committee D19 on Water and is the direct responsibility of Subcommittee D19.03 on Sampling Water and Water-FormedDeposits, Analysis of Water for Power Generation and Process Use, On-Line Water Analysis, and Surveillance
11、 of Water.Current edition approved May 1, 2011June 1, 2017. Published May 2011June 2017. Originally approved in 1952. Last previous edition approved in 20082011 asD1245 08.D1245 11. DOI: 10.1520/D1245-11.10.1520/D1245-17.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contact
12、ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been m
13、ade to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Co
14、pyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2.3.1 DiscussionThe Becke line increases in intensity as the difference in the refractive index between the crystal and the oil increases.3.2.4 dispersion, nthe variation of index of ref
15、raction with wavelength.3.2.5 dispersion staining, nthe color effects produced when a transparent object, immersed in a liquid having a refractiveindex near that of the object, is viewed under the microscope by transmitted white light and precise aperture control.3.2.6 extinction angle, nthe angle b
16、etween the extinction position and some plane, edge, or line in a crystal.3.2.7 extinction position, nthe position in which an anisotropic crystal, between crossed polars, exhibits complete darkness.3.2.8 index of refraction, nthe numerical expression of the ratio of the velocity of light in a vacuu
17、m to the velocity of lightin a substance.3.2.9 isotropic, adjhaving the same optical properties in all directions.3.2.10 petrographic, adjpertaining to the description of rocks or rocklike substances.3.2.10.1 DiscussionSuch description is usually in terms of morphology and optical properties.3.2.11
18、solid solution, na homogeneous mixture of two or more components, in the solid state, retaining substantially thestructure of one of the components.4. Summary of Practice4.1 The practice is essentially chemical microscopical, supplemented by optical data obtained by the petrographic method. Theident
19、ification of compounds is made by observing, under the microscope, characteristic reactions and precipitates resulting fromthe action of specific reagents on the solid sample or solutions thereof, and by measuring the optical properties.5. Significance and Use5.1 Chemical composition of water-formed
20、 deposits is a major indicator of proper or improper chemical treatment of processwater, and is often an indicator of operational parameters as well, for example, temperature control. This practice allows for rapiddetermination of constituents present in these deposits, particularly those indication
21、s of improper water treatment, since theyusually have very distinctive and easily recognized optical properties.5.2 This practice, where applicable, eliminates the need for detailed chemical analysis, which is time-consuming, and whichdoes not always reveal how cations and anions are mutually bound.
22、5.3 Qualitative use of this practice should be limited to those deposits whose control is generally known or predictable, basedon treatment and feedwater mineral content, and whose constituents are crystalline, or in other ways optically or morphologicallydistinctive. If these criteria are not met,
23、other techniques of analysis should be used, such as Practice D2332 or Test MethodsD3483, or both.5.4 Quantitative use of this practice should be limited to estimates only. For more precise quantitative results, other methodsshould be used (see 5.3).6. Interferences6.1 Organic material may interfere
24、 with both the petrographic and the chemical procedures. Organics can usually be removedby solvent extraction as recommended in Practices D2331.6.2 Deposits containing solid solutions present a complication in that optical data vary throughout such a system, and unlessthe presence of this complicati
25、on is known, the data may be misinterpreted.6.3 Extremely fine material and opaque material are difficult to identify. When present in appreciable amounts they may cloudover and obscure details of otherwise recognizable particles.6.4 Interference with the chemical tests will be discussed in the proc
26、edures.7. Apparatus7.1 Beakers, of borosilicate glass, 30-mL.7.2 Cover Glasses, No. 1 or No. 112 thickness, round or square cover glasses.7.3 Glass Rods, 150 by 5-mm, for transferring drops, and 75 by 1-mm, for stirring and leading reagent drops on the slides.7.4 Hotplate.D1245 1727.5 Light SourceMi
27、croscope lamp with concentrated filament bulb and a focusing lens.7.6 Micro Gas Burner.7.7 Micro Spatula.7.8 Microscope Slides, of selected grade, 25.4 by 76.2-mm or 25.4 by 50.8-mm.7.9 Mortar and Pestle, of tool steel, mullite, or aluminum oxide.7.10 Petrographic MicroscopeAmicroscope equipped with
28、 a circular rotating stage, graduated in degrees. The optical systemshall include two polarizing devices, one mounted below the condenser and the other just above the objective; 4, 10, and 45objectives; and 5 and 10 eyepieces fitted with crosshairs. The optic axis of the microscope shall be adjustab
29、le so that it can bebrought into coincidence with the center of rotation of the revolving stage.ABertrand-Amici lens equipped with an iris diaphragm,or a sliding stop ocular, shall be used for viewing interference figures. A quartz wedge, gypsum plate, and standard mica plate arenecessary external a
30、ccessories. Aperture stops are necessary for observing the color effects of dispersion, that is, dispersionstaining. A cardboard “washer” in the objective and a cover glass with a centered dried drop of India ink are sufficient; however,a device is available commercially.7.11 Porcelain Crucibles, No
31、. 0.7.12 Reagent Bottles for Immersion LiquidsGlass dropping bottles of 30-mL capacity. These bottles shall be equipped withgroundglass stoppers with dropping rods integral with the stoppers. Inert plastic bulbs and caps may be used, but dropping bottleswith rubber bulbs are unsatisfactory because o
32、f the effect of some of the immersion liquids on the rubber. It is essential that thebottles be marked with the refractive index of the contained liquid. Commercially available liquids come in dropping bottles whichare acceptable.7.13 Refractometer, for measuring the refractive index of immersion li
33、quids.7.14 Sample Vials, 45 by 15-mm.7.15 Sieve, No. 100 (149 m).7.16 Small Alloy Magnet.8. Reagents8.1 Purity of ReagentsReagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that allreagents shall conform to the specifications of the Committee on Analytical
34、 Reagents of the American Chemical Society, wheresuch specifications are available.3 Other grades may be used, provided it is first ascertained that the reagent is of sufficiently highpurity to permit its use without lessening the accuracy of the determination.8.1.1 Purity of WaterReference to water
35、 that is used for reagent preparation, rinsing or dilution shall be understood to meanwater that conforms to the quantitative specifications of Type II reagent water of Specification D1193.8.2 Ammonium Hydroxide (sp gr 0.90)Concentrated ammonium hydroxide (NH4OH).8.3 Ammonium Molybdate Solution (100
36、 g/L)Dissolve 1 g of ammonium molybdate (NH4)6Mo7O244H2O) in water, add 35mL of nitric acid HNO3 (sp gr 1.42) and dilute to 1 L with water.8.4 Ammonium Persulfate(NH4)2S2O8), crystalline.8.5 Barium Chloride Solution (100 g/L)Dissolve 100 g of barium chloride (BaCl22H2O) in water and dilute to 1 L.8.
37、6 Cesium SulfateCs2SO4 crystals, 10 to 20-mesh.8.7 Chloroform.8.8 Chloroplatinic Acid SolutionDissolve 1 g of chloroplatinic acid H2PtCl66H2O in 5 mL of water and add 0.5 mL of HCl(sp gr 1.19).8.9 Diammonium Phosphate Solution (100 g/L)Dissolve 100 g of diammonium phosphate (NH4)2HPO4 in water and d
38、iluteto 1 L.8.10 Dimethylglyoxime, crystalline.8.11 Hydrochloric Acid (sp gr 1.19)Concentrated hydrochloric acid (HCl).8.12 Hydrochloric Acid (1+4)Mix one volume of HCl (sp gr 1.19) with four volumes of water.8.13 Lead Acetate Test Paper.3 Reagent Chemicals, American Chemical Society Specifications,
39、 American Chemical Society, Washington, DC. For Suggestions on the testing of reagents not listed bythe American Chemical Society, see Annual Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Pharmacopeial Convention, In
40、c. (USPC), Rockville, MD.D1245 1738.14 Nitric Acid (sp gr 1.42)Concentrated nitric acid (HNO3).8.15 Nitric Acid (1+19)Mix one volume of HNO3 (sp gr 1.42) with ten volumes of water.8.16 Phenolphthalein Indicator Solution.8.17 Potassium Ferricyanide K3Fe(CN)6, crystalline.8.18 Potassium Iodide (KI), c
41、rystalline.8.19 Potassium Mercuric Thiocyanate Solution (100 g/L)Prepare freshly precipitated mercuric thiocyanate Hg(CNS)2 byadding a concentrated solution of mercuric nitrate Hg(NO3)2 to a concentrated solution of potassium thiocyanate KCNS. Filter andair-dry the precipitate. To one part Hg(CNS)2
42、add three parts KCNS, dissolve in a minimum quantity of water, and evaporate ina desiccator. Collect the first crop of tabular crystals of potassium mercuric thiocyanate K2Hg(CNS)4, wash with alcohol, and dry.Dissolve 10 g of the crystals in water and dilute to 100 mL.8.20 Refractive Index Standards
43、 StandardsA set of liquids having refractive indices ranging from 1.40 to 1.74 in steps of0.01. In the range from 1.45 to 1.65, it is desirable to have liquids available in steps of 0.005. Commercially available liquids arerecommended; however directions for the preparation of suitable liquids are g
44、iven in U. S. Geological Survey Bulletin No. 848(1) 4 or Elements of Optical Mineralogy(2). The index of refraction of these liquids must be checked prior to their use, as they maychange from loss of more volatile constituents.8.21 Silver Nitrate Solution (50 g/L)Dissolve 50 g of silver nitrate AgNO
45、3 in water, add 20 mL of HNO3 (sp gr 1.42), anddilute to 1 L with water.8.22 Sodium BismuthatePowdered NaBiO3.8.23 Sulfuric Acid (sp gr 1.84)Concentrated sulfuric acid (H2SO4).8.24 Sulfuric Acid (1+19)Add 1 volume of H2SO4 (sp gr 1.84) slowly and with stirring to 19 volumes of water.8.25 Zinc DustPo
46、wdered zinc metal.8.26 Zinc Uranyl Acetate SolutionDissolve 1 g of uranyl acetate UO2(C2H3O2)22H2O and 0.1 mL of glacial acetic acid in5 mL of water. Dissolve 3 g of zinc acetate Zn(C2H3O2)22H2O and 0.1 mL of glacial acetic acid in 5 mL of water. Warm ifnecessary to complete solution. Mix the two so
47、lutions and store in a chemically resistant glass bottle. If precipitation occurs, filterthe solution before use.9. Sampling9.1 Collect the sample in accordance with Practices D887.10. Laboratory Preparation of Samples10.1 Prepare the sample in accordance with Practices D2331.10.2 Place a portion of
48、 the ground sample (approximately 0.1 g or less) in a porcelain crucible, add four drops of HNO3 (sp gr1.42), and evaporate to dryness over the microburner. Add 1 mL of water, warm, and stir with a glass rod. Allow the insolublematerial to settle. Withdraw portions of the supernatant liquid, hencefo
49、rth referred to as the test solution, on the end of a glass rodand transfer to a slide for carrying out certain of the tests described in Section 11.11. Chemical Procedures11.1 The tests in this section are intended as an aid to the petrographic section of this practice. The sensitivity of these testsvaries so that the operator should become familiar with each test to be able to judge semiquantitatively the amount of eachconstituent present based on the amount of sample used and the strength of the reaction observed. Some
